CN1164129A - Semiconductor memory devices - Google Patents

Abstract

The invention provides a semiconductor memorizer in which a redundancy memory cell array 12A, 12B is arranged at an end of a main memory cell array 11A, 11B in the column direction. A disconnection circuit 13A, 13B is arranged between the main memory cell array 11A, 11B and the redundancy memory cell array 12A, 12B. A column selection switch 15A, 15B is arranged at an end of the redundancy memory cell array, so the main memory cell array and the redundancy memory cell array can use the column thread and the column selection switch and the area of the chips is reduced. The area of the chips also can be reduced without the increase of the work procedures by using the redundancy memory cell array whose ROM formed by the stair PROM.

Description

Semiconductor storage unit

The present invention relates to mask ROM semiconductor storage units such as (ROM).

In the past, in mask rom, utilized fuse to be configured for protecting the redundant storage unit of fault memory cell.This fuse is made of polysilicon, and, utilize and to blow or blown fuse not, carry out the storage of data.

But, to compare with the main memory unit that constitutes by MOS transistor, the redundant storage unit that is made of fuse occupies bigger area on semiconductor chip.In addition, for blown fuse, must on this fuse, apply high voltage.

Therefore, as shown in figure 46, the floor plan of mask rom is in the past set for main memory cell array 1 and redundant memory cell array 2 is configured in place separately.

For this reason, need to increase newly the address is deciphered, and the redundant decoder 3 of selecting redundant storage unit to use, also need newly-increased being used for will deliver to the bus 5 of sense amplifier 4 simultaneously from the data of redundant storage unit output.

That is to say that mask rom in the past is because of using fuse, so the shortcoming that has semiconductor area to increase in redundant storage unit.

The present invention is for solving the semiconductor storage unit that aforesaid drawbacks is finished, its objective is in semiconductor storage units such as mask rom, the circuit structure and the lines layout of structure, the floor plan on the chip, redundant circuit and the decoder etc. of the redundant storage unit that can dwindle chip area is provided.

For reaching aforementioned purpose, semiconductor storage unit of the present invention comprises: main memory cell array, the row decoder of the row of described main memory cell array being selected according to first input signal, near the end configuration of the column direction of described main memory unit and with the redundant memory cell array of described main memory cell array shared bit line or alignment, be configured in the cut-out circuit between described main memory cell array and described redundant memory cell array, in abutting connection with the configuration of described redundant memory cell array and the row of described main memory cell array are selected and according to described first or described second input signal column decoder that the row of described redundant memory cell array are selected and the row of described redundant memory cell array is selected and utilized the redundant circuit of described cut-out circuit according to second input signal at described main memory cell array and separated described bit line of described redundant memory cell array or described alignment according to described first or second input signal.

Described main memory cell array is made of the mask rom that can only finish read operation, and described redundant memory cell array is made of one-level PROM.

In described redundant memory cell array, with two publicly-owned source and drain areas of memory cell of column direction adjacency.

The size of the line direction of described redundant memory cell array is the integral multiple of size of the line direction of described main memory cell array.

Here, so-called line direction is the direction parallel with word line, and so-called column direction is the direction parallel with alignment or bit line.

Described redundant circuit has the storage area of the row of the defective memory cell that is used to store described main memory cell array, going and the capable consistent occasion of utilizing described first input signal to select of the described storage area of storage, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array.

Described redundant circuit has the memory cell of the row of the defective memory cell that is used to store described main memory cell array, the row of the unit storage area occasion consistent in described storage with the row that utilize described second input signal, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array, simultaneously described first input signal is delivered in the described column decoder, selected the row of redundant memory cell array according to described first input signal.

By the first and second crystal nest of tubes, transmitting the holding wire of described first input signal and the holding wire of described second input signal of transmission interconnects, described column decoder is connected on the holding wire between the described first and second crystal nest of tubes, by means of control the described first and second crystal nest of tubes conducting and end, described first or second input signal is sent in the described column decoder.

Described redundant circuit has the row of the defective memory cell that is used to store described main memory cell array or the memory cell of row, row of in described storage area, storing or row and row that utilizes described first or second input signal to select or the consistent occasion of row, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array, simultaneously described first or second input signal is delivered in the described column decoder, selected the row of described redundant memory cell array according to described first or second input signal.

By first, the second and the 3rd crystal nest of tubes, transmitting the holding wire of described first input signal and the holding wire of described second input signal of transmission interconnects, described column decoder is connected on the holding wire between the described first and second crystal nest of tubes, the selection circuit of the row of described cut-out circuit and described selection redundant memory cell array is connected on the holding wire between the described second and the 3rd crystal nest of tubes, by means of control described first, the conducting of the second and the 3rd crystal nest of tubes and ending, described first or second input signal is sent in the described column decoder, and first or second input signal is sent in the described selection circuit.

Described semiconductor storage unit has the bit line and the alignment of mutual configuration, described main memory cell array is made of the memory cell that is connected between bit line and the alignment, described redundant memory cell array is made of the memory cell that is connected between alignment and the alignment, the alignment of described bit line and regulation is connected in the sense amplifier, and described alignment is connected to be provided in the biasing circuit of regulation current potential each alignment.

In addition, the memory cell of described redundant memory cell array also can be connected between bit line and the bit line.

When the data of the memory cell of reading described main memory cell array, described biasing circuit alternatively is applied to earthing potential and bias potential on the described alignment, when the data of the memory cell of reading described redundant memory cell array, described biasing circuit makes described alignment be added with earthing potential every one, and the alignment that will not apply earthing potential is connected in the sense amplifier.

Also comprise and provide the regulation current potential described alignment, and data are write the write circuit of using in the memory cell of described redundant memory cell array, when the said write circuit write data in the memory cell of described redundant memory cell array, described redundant circuit utilized described cut-out circuit to disconnect described bit line or described alignment.

Outer more than one first bonding pad that the current potential that data write the memory cell of described redundant memory cell array and provide uses and more than one second bonding pad that is used to add the power supply potential that makes the semiconductor storage unit running of adding as is provided, after data are write the memory cell of described redundant memory cell array, described power supply potential is applied on described first bonding pad and described second bonding pad simultaneously.

For the radical by bit line in the described redundant memory cell array or alignment is lacked than the radical by bit line in the described main memory cell array or alignment, decoder is configured between described redundant memory cell array and described main memory cell array.

Semiconductor storage unit of the present invention comprises: main memory cell array, the row decoder of the row of described main memory cell array being selected according to first input signal, the column decoder of the row of described main memory cell array being selected according to second input signal, redundant memory cell array, redundant circuit of the row of described redundant memory cell array being selected according at least one signal in described first and second input signals and the column decoder of the row of described redundant memory cell array being selected according to described first or second input signal.

Fig. 1 represents the floor plan of semiconductor storage unit of the present invention.

Fig. 2 represents the plane graph of the part of semiconductor storage unit of the present invention.

Fig. 3 represents along the cutaway view of III-III line among Fig. 2.

Fig. 4 represents along the cutaway view of IV-IV line among Fig. 2.

The equivalent circuit diagram of one-level PROM in Fig. 5 presentation graphs 2.

Fig. 6 represents the circuit diagram of the row decoder of semiconductor storage unit of the present invention.

Fig. 7 represents the circuit diagram of the redundant circuit of semiconductor storage unit of the present invention.

Fig. 8 represents the circuit diagram of the column decoder of semiconductor storage unit of the present invention.

Fig. 9 represents the circuit diagram of the memory cell array of semiconductor storage unit of the present invention.

Figure 10 represents the figure of planar graph of the memory cell array of semiconductor storage unit of the present invention.

Figure 11 represents the circuit diagram of the redundancy unit of semiconductor storage unit of the present invention.

Figure 12 represents the circuit diagram of the redundancy unit of semiconductor storage unit of the present invention.

Figure 13 represents the block diagram of semiconductor storage unit of the present invention.

Figure 14 represents the precedence diagram of reading of semiconductor storage unit among Figure 13.

Figure 15 represents the concept map of the semiconductor storage unit of memory bank.

Figure 16 represents the concept map of the semiconductor storage unit of memory bank.

Figure 17 represents the equivalent circuit diagram of memory bank formula mask rom.

Figure 18 represents the figure that the part taking-up of main memory cell array is represented.

Figure 19 represents the planar graph of memory cell array among Figure 18.

Figure 20 represents the circuit diagram of main memory cell array unit and redundant memory cell array unit.

Figure 21 represents the planar graph of memory cell array among Figure 20.

Figure 22 represents the circuit diagram of column decoder unit, write circuit unit and reading circuit unit.

Figure 23 represents the circuit diagram of the control grid selection circuit of redundant storage array.

Sequential chart when Figure 24 represents to protect main memory unit.

Figure 25 represents the circuit diagram of row address memory circuit.

Figure 26 represents the circuit diagram of column address memory circuit.

Figure 27 represents the circuit diagram of level shifter.

Figure 28 presentation address is write fashionable block diagram.

Figure 29 presentation address is write fashionable precedence diagram.

Figure 30 represents to write the circuit diagram of pattern detection circuit.

Figure 31 is illustrated in the state potential diagram that writes.

Figure 32 represents the circuit diagram of redundancy control circuit.

The precedence diagram of Figure 33 presentation address verification.

The figure of Figure 34 presentation address detecting operation.

Figure 35 represents the precedence diagram of redundancy control circuit.

Figure 36 represents that data write fashionable precedence diagram.

Figure 37 represents the circuit diagram of the preposition address translation circuit of row among Figure 13.

Figure 38 represents the power supply diagram about semiconductor storage unit of the present invention.

Figure 39 represents the block diagram of semiconductor storage unit of the present invention.

Figure 40 represents the circuit diagram of redundancy control circuit.

Figure 41 represents the address storage circuit of semiconductor storage unit among Figure 39.

Precedence diagram when Figure 42 represents to read about the address.

Figure 43 represents the figure of the part of semiconductor storage unit of the present invention.

Figure 44 represents the block diagram of semiconductor storage unit of the present invention.

The figure of Figure 45 presentation address memory circuit.

Figure 46 represents the floor plan of semiconductor storage unit in the past.

Below, the embodiment to semiconductor storage unit of the present invention at length describes with reference to accompanying drawing.

Embodiment

(A) the following examples relate generally to structure, the floor plan on the chip, circuit structure and the lines layout of redundant storage unit.

Fig. 1 represents the floor plan of the semiconductor storage unit relevant with embodiments of the invention.

Row decoder 10 is configured between two main memory cell array 11A and the 11B.That is, two main memory cell array 11A and the public row decoder 10 of 11B.

To cut off circuit 13A is configured between main memory cell array 11A and the redundant memory cell array 12A.Cutting off circuit 13A is electrically connected main memory cell array 11A and redundant memory cell array 12A or dead circuit.About cutting off concrete structure and the operation of circuit 13A, will be described in detail below.

Equally, will cut off circuit 13B is configured between main memory cell array 11B and the redundant memory cell array 12B.Cutting off circuit 13B is electrically connected main memory cell array 11B and redundant memory cell array 12B or dead circuit.About cutting off circuit 13B concrete structure and operation are arranged, narration at length below.

With the width of the line direction of the width of the line direction of main memory cell array 11A, 11B and redundant memory cell array 12A, 12B, set for identical.

Here, in whole explanations below, line direction and column direction are defined as follows.That is, the direction parallel with the word line (the perhaps control grid of redundant memory cell array) of main memory cell array be as line direction, and the direction parallel with the alignment of main memory cell array and redundant memory cell array or bit line is as column direction.

Redundant circuit 14 is configured in redundant memory cell array 12A and cut-out circuit 13A and redundant memory cell array 12B and cuts off between the circuit 13B.Redundant circuit 14 is circuit that fault memory cell is replaced as redundant storage unit and this redundant storage unit is carried out read operation.

Column decoder 15A is configured to the adjacency with redundant memory cell array 12A, and column decoder 15B is configured to the adjacency with redundant memory cell array 12B.

Sense amplifier 16A is configured to the adjacency with column decoder 15A, and sense amplifier 16B is configured to the adjacency with column decoder 15B.Biasing circuit 17A is configured to the adjacency with main memory cell array 11A, and biasing circuit 17B is configured to the adjacency with main memory cell array 11B.

Bonding pad 18A and 18B be configured in respectively with semiconductor chip 19 mutual opposed two edge parts on.

In the configuration of each square frame shown in the aforementioned floor plan, main memory cell array 11A, redundant memory cell array 12A, cut-out circuit 13A, column decoder 15A, sense amplifier 16A are connected multiple bit lines (perhaps alignment) jointly with biasing circuit 17A.

Equally, main memory cell array 11B, redundant memory cell array 12B, cut off circuit 13B, array decoding circuit 15B, read amplification appliance 16B and also be connected multiple bit lines (perhaps alignment) jointly with biasing circuit 17B.

Adopt this configuration, then make redundant memory cell array 12A and 12B be configured to approach main memory cell array 11A and 11B, and the width of the line direction of main memory cell array 11A and 11B is equated with the width of the line direction of redundant memory cell array 12A and 12B.

Therefore, if column decoder 15A is configured to be adjacent to redundant memory cell array 12A, then energy common column decoder 15A among main memory cell array 11A and the redundant memory cell array 12A does not need special-purpose column decoder in redundant memory cell array 12A.

Equally, if column decoder 15B is configured to be adjacent to redundant memory cell array 12B, then energy common column decoder 15B among main memory cell array 11B and the redundant memory cell array 12B does not need special-purpose column decoder in redundant memory cell array 12B.

In addition, in main memory cell array 11A, redundant memory cell array 12A, cut-out circuit 13A, column decoder 15A, sense amplifier 16A and biasing circuit 17A, many bit lines of shared connection (perhaps alignment) are not so need to be used for the data of the memory cell of redundant memory cell array 12A are sent to the new bus of sense amplifier.

Equally, in main memory cell array 11B, redundant memory cell array 12B, cut-out circuit 13B, column decoder 15B, sense amplifier 16B and biasing circuit 17B, shared connection multiple bit lines (perhaps alignment).So do not need to be used for the data of the memory cell of redundant memory cell array 12B are sent to the new bus of sense amplifier.

Like this, adopt floor plan of the present invention, then can the downsizing of semiconductor chip be contributed.

Fig. 2 represents the plane graph of the part of the semiconductor storage unit relevant with embodiments of the invention.

In addition, in Fig. 2, generally oblique line partly is called SDG (source electrode, drain electrode, grid) zone.In this SDG zone, form the n that imbeds as the imaginary earth connection of mask rom unit and alignment ⁺The zone, thus the word line (control grid) of redundant memory cell array and source electrode, drain region formed.

The figure expression is along the cutaway view of III-III line among Fig. 2, and Fig. 4 represents that Fig. 5 represents the equivalent circuit diagram of one-level PROM along the cutaway view of IV-IV line among Fig. 2.

The present invention uses " one-level PROM " in the redundant storage unit of the semiconductor storage unit (especially mask rom) of for example Fig. 1.

On semiconductor chip 20, form field oxide film 21.On semiconductor chip 20, also form and follow the many word lines (control grid) 22 that direction is extended.Word line 22 is made of diffusion layer, and disposes regularly with predetermined distance.

The a plurality of floating grids 23 of configuration on word line 22.Floating grid 23 is made of the polysilicon that contains impurity and has a T-shaped shape.

On the semiconductor chip under the part of floating grid 23 20, form transistor channel.Formation source, drain region 24A, 24B in the semiconductor chip 20 at these raceway groove two ends.Source, drain region 24A, 24B are made of diffusion layer.

Source, drain region 24A, 24B are connected to along in the multiple bit lines (perhaps alignment) 25 of column direction extension.Bit line (alignment) 25 is made of aluminium, also is connected in the main memory unit.

In addition, the one-level PROM that adjoins each other (redundant storage unit) M1, M2 have source, drain region 24A, 24B.

Use in the semiconductor storage unit of aforementioned one-level PROM at redundant storage unit, it especially is the occasion of the mask rom that constitutes by MOS transistor at main memory unit, because of the bit line (perhaps alignment) of the bit line (perhaps alignment) of main memory unit and redundant storage unit can be shared, so the column decoder of the column decoder of main memory unit and redundant storage unit also can be shared.

Therefore, do not need column decoder special-purpose in the redundant memory cell array, can dwindle the area of semiconductor chip.

Because of the polysilicon that utilizes ground floor can form the grid of main memory unit and the floating grid of redundant storage unit simultaneously, so can not increase the worker ordinal number, also can not increase expense.

Fig. 6 represents the circuit diagram of the row decoder of semiconductor storage unit of the present invention.

For example, from 8 PHWA groups, select 1, on 1 selected PHWA, supply with high potential VDD, on 7 remaining PHWA, supply with electronegative potential VSS.Here, select 1 from 8 PHWB groups, when supplying with electronegative potential VSS on 1 selected PHWB, MOS transistor A, B become conducting state, thereby the current potential that the current potential of node D becomes the word line of " H " level and regulation also becomes " H " level.

Any one is the occasion of conducting state in MOS transistor A and MOS transistor B, by resistance E node D is connected to earth point, thereby the current potential of the word line that is connected with this node D becomes " L " level.

When MOS transistor A and MOS transistor B conducting and PHWA were " L " level, the current potential of word line also became " L " level.

In addition, PHWC group and PHWD group are used for selecting 1 word line from many word lines.The 26th, main decoder.

Fig. 7 represents the circuit diagram of the redundant circuit of semiconductor storage unit of the present invention.

The whole memory cell that the present invention relates to be used for being connected with 1 word line of main memory cell array are replaced as the redundant circuit of redundant storage unit.

At first, the method that is used to store the address that is replaced as redundant storage unit is described.From address bonding pad Input Address signal, in address decoder,, and generate PHWA group's etc. signal to the decoding of this address signal.

In the present invention, in order to be replaced as redundant storage unit, do not use the address signal of specify columns here with whole memory cell that 1 word line in the main memory cell array is connected.

Select in displacement and the main memory cell array delegation of the redundant memory cell array of whole memory cell that 1 word line is connected, and import the address signal of this row of selection.

With select these main memory cell arrays word line address signal and select the address signal of the word line of redundant memory cell array, (for example be stored in the storage area that has in the redundant circuit respectively, the same with redundant storage unit, also constitute by one-level PROM) among the ME.

That is to say that 1 bit line (drain electrode of memory cell) that level shift circuit B ' stipulates provides and writes current potential VPP in storage area ME for example.1 word line (the control grid of memory cell) that level shift circuit C ' stipulates in storage area ME for example provides and writes current potential VPP.

Add among the storage unit groups A ' that writes current potential VPP in drain electrode, electronics is injected the control grid also add the memory cell floating grid that writes current potential VPP, and data (address signal) are write in this memory cell.

Then, system of selection and the date storage method to redundant storage unit describes.When from outside Input Address signal, judge whether the address of this address signal is consistent with address stored among the storage area ME.If the address of address signal is consistent with address stored among the storage area ME, then the current potential of node D becomes " H " level.

The current potential of node E also becomes " H " level, and current potential shifter circuit L output writes current potential VPP.Utilize column decoder CDE, select in the redundant storage unit one in the many word lines.

Therefore, in redundant memory cell array, on selected 1 word line, apply and write current potential VPP.

In addition, in the size of the line direction of redundant storage unit the 2n occasion doubly of size of the line direction of main memory unit, when protection was connected in whole memory cell on 1 word line of main memory cell array, the line number that redundant memory cell array needs was 2n.

In this occasion, utilize the CDE of column decoder, select the 2n root word line of redundant memory cell array.

As shown in Figure 8, on the bit line (perhaps alignment) of the regulation of redundant memory cell array, by column decoder CDE ' add the current potential of regulation and with storage in redundant storage unit.

Then, the method from the redundant storage unit sense data is described.When from outside Input Address signal, utilize address decoder that address signal is carried out decoder and generates PHWA etc.

For example, if select among 8 PHWA 1, the current potential of 1 then selected PHWA (node G) becomes this " H " level.Here, the power supply potential of level shift circuit C ' is to write current potential VPP in the stage that writes data to redundant storage unit, but becomes conventional current potential VDD afterwards.

Therefore, the current potential of the word line of transistor I becomes " H " level, in the occasion (in the occasion of electronics being injected floating grid) that data is write in this transistor I, electric current does not flow in this transistor I, in the occasion (electronics not being injected the occasion of floating grid) that data is not write in this transistor I, electric current flows in this transistor I.

Equally, if whole transistors of the A ' group of the holding wire that is connected in PHWB group and elects from the signal of selecting the address are write, then electric current is mobile in whole transistors of A ' group, and node D becomes " H " level.

Yet it is fashionable to have at least an existence not carry out writing of data in the transistor about A ' group, because of electric current in this transistor flows, so node D becomes " L " level.

When reading the data of redundant storage unit, node J is " H " level, thereby for example by cutting off circuit main memory cell array is disconnected from sense amplifier, and the data of coming from main memory cell array are not output.

Fig. 9 and Figure 10 represent the structure of the memory cell array unit of semiconductor storage unit of the present invention.

The draw circuit diagram of annexation of expression main memory cell array, redundant memory cell array and cut-out circuit of Fig. 9.The lines layout of configuration relation that Figure 10 draws expression main memory cell array, redundant memory cell array and cut-out circuit.

Because the size of the line direction of redundant storage unit is set 8 times of size of the line direction of main memory unit for, for example, if 8 row of classifying as of classifying 64 row, redundant memory cell array as of main memory cell array, then the width of the line direction of main memory cell array equates with the width of the line direction of redundant memory cell array.

In addition, make the alignment of the alignment of main memory cell array and redundant memory cell array shared, configuration cuts circuit between main memory cell array and redundant memory cell array.

This cut-out circuit when writing data in the redundant storage unit, has not add and writes the function of current potential VPP to the main memory unit, when sense data from redundant storage unit, has the function that does not send from the data of main memory cell array simultaneously.

Below, the action of the column decoder during to the data of reading main memory unit describes simply.For example, when selecting the holding wire K of Fig. 8, a bit line B1 just is connected in the sense amplifier 31, and one is connected to biasing circuit 32 in two alignment C1, C2 of its both sides configuration, and another root is connected to earth point.

In addition, when reading the data of redundant memory cell array, because of for example alignment C1 or sense amplifier alignment C2 are connected with VSS, so read the data that are connected in the redundant storage unit between alignment C1 and sense amplifier alignment C2.

[B] the following examples relate to and only are used in line direction the redundant storage unit method is set, and reach the protection of the line direction and the column direction of main memory unit.

Figure 11 represents the circuit structure of semiconductor storage unit of the present invention.

The redundant memory cell array that utilization of the present invention only is provided with in an end of the column direction (perhaps line direction) of main memory cell array carries out the protection to the memory cell of the protection of the memory cell of the line direction of main memory cell array and column direction.

In the following description, for the sake of simplicity, suppose that main memory cell array has 4 row 4 row, and only form redundant memory cell array in an end of the column direction of main memory cell array.

Four alignment COL1-COL4 are configured in the main memory cell array 41 respectively, cut off in the circuit 42, in the redundant memory cell array 43 and in the column decoder 44.

Main memory cell array 41 constitutes by being configured to the different MOS transistor of 4 * 4 ranks shapes and threshold value.Cutting off circuit 42 is made of MOS transistor.Redundant memory cell array 43 is made of the ranks shape and the different one-level PROM of threshold value that are configured to 4 * 1.Column decoder 44 with among four alignment COL1-COL4 selected 1 be connected in the sense amplifier 45.

Four word line W1-W4 are connected in the row decoder 46 in the main memory cell array 41.Row decoder 46 can be connected in series by for example NAND circuit and inverter circuit and constitute.To be input in the row decoder 46 such as output signal  A1,  A2,  B1, the  B2 of the preposition decoder of row.Row decoder 46 is selected a word line according to output signal  A1,  A2,  B1,  B2, and high potential VDD is offered on the selected word line.

Output signal  A1,  A2,  B1, the  B2 of the preposition decoder of row also are input in the row address memory circuit 47.

The occasion that has out of order memory cell in main memory cell array 41 will select the row address of the row (word line) of fault memory cell existence to be stored in the row address memory circuit 47.

Here, in output signal  A1,  A2 that the row (word line) of selecting the fault memory cell existence is provided, the occasion of  B1,  B2 (row address), the output signal of row address memory circuit 47 output " L " level.

Therefore, the MOS transistor of cutting off circuit 42 all is in cut-off state, at main memory cell array 41 and redundant memory cell array 43 separated alignment COL1-COL4.

In addition, when the memory cell of line direction was protected, crystal nest of tubes A was a cut-off state, and crystal nest of tubes B sets conducting state for.

The occasion that in main memory cell array 41, has fault memory cell; when the memory cell of line direction is protected; output signal CA1, CA2, CB1, the CB2 of the preposition decoder of row are provided in the column decoder 44; when the memory cell of column direction is advanced to protect, output signal CA1, CA2, CB1, the CB2 that is listed as preposition decoder only is provided in the column address memory circuit 48.

To select the column address of the row (alignment) of fault memory cell existence to be stored in the column address memory circuit 48.

Here, in the output occasion that the row (alignment) of selecting the fault memory cell existence are provided, the output signal of column address memory circuit 48 output " L " level.

Therefore, the MOS transistor of cutting off circuit 42 all is in cut-off state, at main memory cell array 41 and redundant memory cell array 43 separated alignment COL1-COL4.

In addition, when the memory cell of column direction was protected, crystal nest of tubes A became conducting state, and transistor B sets cut-off state for.

Then, there is action to describe to the aforesaid semiconductor memory device.

At first, the protection of the memory cell of line direction is investigated.Four memory cell 1-4 that supposition now will connect word line WL2 are replaced as redundant storage unit.In this occasion, the storage of selecting output signal  A1,  A2,  B1, the  B2 of word line WL2 is expert in the address storage circuit 47.Crystal nest of tubes A is configured to conducting state, and crystal nest of tubes B is configured to cut-off state.

When output signal  A1,  A2 that the preposition decoder of row is provided,  B1,  B2, row address memory circuit 47 just judges whether that output signal  A1,  A2,  B1,  B2 select word line WL2.

In the occasion of output signal  A1,  A2,  B1,  B2 selection word line WL2, the output signal of row address memory circuit 47 output " L " level.Therefore, the MOS transistor of cutting off circuit 42 all becomes conducting state, at main memory cell array 41 and redundant memory cell array 43 separated alignment COL1-COL4.

Therefore, utilize row decoder 46 to select word line WL2, the data of memory cell 1-4 are outputed among the alignment COL1-COL4, but reason cuts off circuit 42 and cut off alignment COL1-COL4, so these data can be sent in the sense amplifier 45.

On the other hand, on word line (for example redundant storage unit is the control grid of the occasion of the one-level PROM) WR of redundant memory cell array, add the current potential of " H " level, thereby the data of redundant storage unit 1-4 are outputed among the alignment COL1-COL4.

Output signal CA1, CA2, CB1, the CB2 of the preposition decoder of row are input in the column decoder 44, and only an alignment are connected in the sense amplifier 45.Therefore, only amplify the data of selected row and output to the outside by sense amplifier 45.

Then, the protection of the memory cell of column direction is investigated.Four storage unit A-D that supposition now will connect alignment COL2 are replaced as redundant storage unit.In this occasion, will select the storage of output signal CA1, CA2, CB1, CB2 of alignment COL2 in column address memory circuit 48.Crystal nest of tubes A is configured to cut-off state, and crystal nest of tubes B is configured to conducting state.

When output signal CA1, CA2 that the preposition decoder of row is provided, CB1, CB2, column address memory circuit 48 just judges whether that output signal CA1, CA2, CB1, CB2 select alignment COL2.

In the occasion of output signal CA1, CA2, CB1, CB2 selection alignment COL2, the output signal of column address memory circuit 48 output " L " level.Therefore, the MOS transistor of cutting off circuit 42 all becomes cut-off state, at main memory cell array 41 and redundant memory cell array 43 separated alignment COL1-COL4.

On the other hand, on word line (for example redundant storage unit is the control grid of the occasion of the one-level PROM) WR of redundant memory cell array, add the current potential of " H " level, the data of redundant storage unit 1-4 are outputed among the alignment COL1-COL4.

Output signal  A1,  A2,  B1, the  B2 of the preposition decoder of row are input in the column decoder 44, and only an alignment are connected in the sense amplifier 45.Therefore, only amplify the data and the output row outside of selected row by sense amplifier 45.

That is to say, in the occasion that the memory cell of column direction is protected, at first, export four data, and therefrom determine delegation with column decoder 44 (it is more definite perhaps to be called row decoder) from the column direction of redundant storage unit.

Then, to not existing the occasion of trouble unit to describe in the main memory cell array 41.

This occasion, because of storage line address date not in the address storage circuit 47 of being expert at, and in column address memory circuit 48 memory row address date not, so the output signal of row address memory circuit 47 and column address memory circuit 48 is " H " level usually simultaneously.

Therefore, the MOS transistor of cut-out circuit 42 all is a conducting state.That is to say that the data of the memory cell that is connect on the word line of being chosen by row decoder 46 output among the alignment COL1-COL4.And only a number of being chosen by column decoder 44 in these data is reportedly delivered in the sense amplifier 45.

Adopt the semiconductor storage unit of aforementioned structure; then reach the occasion of protection of the memory cell of the protection of memory cell of line direction and column direction at the same time; it is just enough that redundant memory cell array only need be arranged on an end of the end of column direction of main memory cell array or line direction, needn't be arranged on the end both sides of the end of column direction and line direction.

That is to say that for example the occasion of previous embodiment when the memory cell of guard rows direction, can be read the data of the memory cell of line direction from redundant memory cell array, and utilize column decoder to select row to replace.When the memory cell of protection column direction, can read the data of the memory cell of column direction from redundant memory cell array, the output signal of the preposition decoder of row is input in the column decoder, utilize column decoder to select to advance line replacement.

Therefore, can not increase the area of semiconductor chip, and can reach the protection of the memory cell of the protection of memory cell of line direction and column direction simultaneously.

Shown in Figure 12 is the circuit formation of semiconductor storage unit of the present invention.

The present invention is identical with foregoing invention, becomes to carry out the protection of main memory cell array line direction memory cell and the protection of column direction memory cell by the redundant memory cell array of only being located at main memory cell array column direction (or line direction) end.

Below in the explanation, in order to simplify, suppose that main memory cell array has 4 row and 4 row, redundant memory cell array only is formed at main memory cell array column direction one end.

4 alignment COL1～COL4 are configured in the main memory cell array 41 respectively, cut off in the circuit 42, in the redundant memory cell array 43 and in the column decoder 44.

Main memory cell array 41 constitutes by being configured to the different MOS transistor of 4 * 4 ranks shapes, threshold value.Cutting off circuit 42 is made of MOS transistor.Redundant memory cell array 43 constitutes by being configured to the different one-level PROM of 4 * 1 ranks shapes, threshold value.Column decoder 44 with in 4 alignment COL1～COL4 ground selected 1 be connected with sense amplifier 45.

4 word line WL1～WL4 of main memory cell array 41 are connected with row decoder 46.Row decoder 46 can be made of the circuit that for example NAND (NAND) circuit is connected in series with negative circuit.The for example capable preposition decoder output signal  A1 of row decoder 46 inputs,  A2,  B1,  B2.Row decoder 46 is selected 1 word line according to output signal  A1,  A2,  B1,  B2, gives this 1 selected word line high potential VDD.

Output signal  A 1, the  A2 of the preposition decoder of row,  B1,  B2 are also by transistor group A, B Input Address memory circuit 49.

When there was out of order memory cell in main memory cell array 41, when carrying out the line direction protection, address storage circuit 49 stored this fault memory cell row address that (word line) select of being expert at.

Here, provide when fault memory cell is expert at output signal  A1,  A2 that (word line) select,  B1,  B2 (row address) address storage circuit 49 output " L " level output signals.

Thereby the MOS transistor of cutting off circuit 42 all is in cut-off state, cuts off alignment COL1～COL4 between main memory cell array 41 and redundant memory cell array 43.

When there is fault memory cell in main memory cell array 41; when carrying out the protection of line direction memory cell; to be listed as preposition decoder output signal CA1, CA2, CB1, CB2 and offer column decoder 44; but when carrying out the column direction protect bit cell, be listed as preposition decoder output signal CA1, CA2, CB1, CB2 and only offer address storage circuit 49.

When there was fault memory cell in main memory cell array 41, when carrying out the column direction protection, address storage circuit 49 stored the column address that fault memory cell column (alignment) is selected.

Here, when providing output signal CA1, CA2 that fault memorizer unit column (alignment) is selected, CB1, CB2 (column address), address storage circuit 49 output " L " level output signals.

Thereby the MOS transistor of cutting off circuit 42 all is in cut-off state, cuts off alignment COL1～COL4 between main memory cell array 41 and redundant memory cell array 43.

Specifically, the present invention compares with foregoing invention, and difference is that with redundant storage unit being selected the row address memory circuit of usefulness and column address memory circuit gather be one, constitutes address storage circuit.

Next the action of above-mentioned semiconductor storage is described.

At first investigate protection to the line direction memory cell.Supposition now allows redundant storage unit replace 4 memory cell 1～4 that are connected with word line WL2.At this moment, address storage circuit 49 stores output signal  A1,  A2,  B1, the  B2 data that word line WL2 is selected.

And shown in following table 1, transistor group A, B are set at conducting state, and transistor group C is set at cut-off state.

Offer row decoder output signal  A1,  A2,  B1,  B2, address decoding circuitry 49 judges whether output signal  A1,  A2,  B1,  B2 select word line WL2.

Output signal  A1,  A2,  B1,  B2 are that address storage circuit 49 is just exported " L " level output signal when selecting word line WL2.Thereby the MOS transistor of cutting off circuit 42 all is in cut-off state, cuts off alignment COL1～COL4 between main memory cell array 41 and redundant memory cell array 43.

So, select word line WL2 by row decoder 46, the data of main memory device unit 1～4 are exported to alignment COL1～COL4, but cut off alignment COL1～COL4, thereby these data are not given sense amplifier 45 by cutting off circuit 42.

On the other hand, the word line of redundant memory cell array (the control grid when for example redundant storage unit is one-level PROM) WR is added with " H " level current potential, and the data of redundant storage unit 1～4 are exported to alignment COL1～COL4.

After this, as shown in table 1, transistor group B, C are in conducting state, and transistor group A is in cut-off state.

And output signal CA1, the CA2, CB1, the CB2 that are listed as preposition decoder input to column decoder 44, only 1 alignment are connected with sense amplifier 45.Thereby, only amplify selected columns certificate by sense amplifier 45, export the outside to.

Next investigate protection to the column direction memory cell.Supposition now allows redundant storage unit replace 4 storage unit A-D that are connected with alignment COL2.At this moment, address storage circuit 49 stores output signal CA1, CA2, CB1, the CB2 data that alignment COL2 is selected.

As shown in table 1, transistor group A, C are set at conducting state, and transistor group B is set at cut-off state.

Offer the preposition decoder output signal CA1 of row, CA2, CB1, CB2, address storage circuit 49 judges whether output signal CA1, CA2, CB1, CB2 select alignment COL2.

Output signal CA1, CA2, CB1, CB2 are that address storage circuit 49 is just exported " L " level output signal when selecting alignment COL2.Thereby the MOS transistor of cutting off circuit 42 all is in cut-off state, cuts off alignment COL1～COL4 between main storage unit array 41 and redundant memory cell array 43.

On the other hand, the word line of redundant memory cell array (the control grid when for example redundant storage unit is one-level PROM) WR is added with " H " level current potential, and the data of redundant memory unit 1～4 are exported to alignment COL1～COL4.

Output signal  A1,  A2,  B1, the  B2 of the preposition decoder of row input to column decoder 44, only 1 alignment are connected with sense amplifier 45.Thereby, only amplify selected line data by sense amplifier 45, export the outside to.

Specifically, when the column direction memory cell is protected, at first, in the middle of this, determine delegation by column decoder (being called row decoder may be more definite) 44 from 4 data of redundant storage unit output column direction.

Next illustrate that there is not the situation of fault memory cell in main storage unit array 41.

At this moment, as shown in table 1, transistor group B, C are set at conducting state, and transistor group A is set at cut-off state.

And address storage circuit 49 is storage line address date and column address data not, so the output signal of address storage circuit 49 " H " level always.

Thereby the MOS transistor of cutting off circuit 42 all is in cut-off state.That is to say that the data of the memory cell that is connected with the word line of row decoder 46 selections export alignment COL1～COL4 to, only have column decoder 44 selected data to give sense amplifier 45 in the middle of these data.

Table 1

	The line direction protection		The column direction protection		When main memory cell array is read
						When row detects	When the row protection is read	When row detect	When the row protection is read
	Transistor group A	Conducting	End	Conducting						Conducting	End
Transistor group B					Conducting	Conducting	End	End	Conducting
	Transistor group C	End	Conducting	Conducting						Conducting	Conducting

Semiconductor storage unit according to above-mentioned formation; finish the line direction memory cell simultaneously and during to the protection of column direction memory cell; as long as redundant memory cell array is located at main memory cell array column direction one end or line direction one end, do not need to be located at column direction end and two places, line direction end.

Specifically,, when the line direction memory cell is protected, can read line direction main memory unit data, select row to replace by column decoder from redundant memory cell array in the occasion of for example the foregoing description.And when the column direction memory cell protected, can read column direction main memory unit data from redundant memory cell array, and the output signal of the preposition decoder of row is inputed to column decoder, select row to replace by column decoder.

Thereby, can be under the situation that semiconductor area does not increase, finish simultaneously to the protection of line direction memory cell with to the protection of column direction memory cell.

[C] following examples relate generally to floor plan, circuit structure and the lines layout on the chip.

Figure 13 illustrates the block diagram of semiconductor storage unit of the present invention.

Be prerequisite with the mask rom in the present embodiment.And, in order to simplify following explanation, suppose that main memory cell array has Unit 32 at line direction, at column direction Unit 64 are arranged, 4 I/O terminals are arranged.

And the base unit size of row protection and block protection is identical with embodiment before this, and row is 1 word line (Unit 64) when replacing, and piece is line direction Unit 2, column direction Unit 16 when replacing.

The structure of this semiconductor storage unit at first is described.

Main memory cell array 51A, 51B, 51A ', 51B ' by a plurality of threshold values with whether storage being arranged and different MOS transistor constitutes.Redundant memory cell array 52A, 52B, 52A ', 52B ' by a plurality of threshold values with whether storage being arranged and different one-level PROM constitutes.According to this configuration, can make the alignment of the alignment of main memory cell array and redundant memory cell array shared, and make column decoder also shared, thereby can make main memory cell array and redundant memory cell array approaching, help dwindling of semiconductor chip.

Main memory unit is made of MOS transistor, and when redundant storage unit was made of one-level PROM, the size of MOS transistor and one-level PROM's was big or small different, thereby the 2n that the line direction size of one-level PROM can be set at MOS transistor line direction size doubly.

For example, as shown in this embodiment, one-level PROM line direction size is set at 8 of MOS transistor line direction size, a main memory cell array is when line direction disposes Unit 32, if a redundant memory cell array disposes the words of Unit 4 at column direction, the redundant memory cell array column pitch is 8 times of main memory cell array column pitch, so redundant memory cell array line direction width is consistent with main memory cell array line direction width.

Dispose between main memory cell array 51A, 51B, 51A ', 51B ' and redundant memory cell array 52A, 52B, 52A ', the 52B ' bit line column decoder 53,53 ' and cut off circuit 54,54 '.

The columns of main memory cell array 51A, 51B, 51A ', 51B ' is more than the columns of redundant memory cell array 52A, 52B, 52A ', 52B ', thereby, bit line column decoder 53,53 ' have reduces main memory cell array 51A, 51B, 51A ', 51B ' columns, the function that is connected with redundant memory cell array 52A, 52B, 52A ', 52B '.

Cut-out circuit 54,54 ' have when the memory cell to redundant memory cell array 52A, 52B, 52A ', 52B ' writes data, with from this memory cell sense data the time, between main memory cell array and redundant memory cell array, cut off the function of alignment.

Row decoder 55,55 ' have is according to the output signal of main preposition decoder 56 of row and the preposition decoder 57 of row, the function that the word line of main memory unit 51A, 51B, 51A ', 51B ' is selected.

Column decoder 58 has the output signal according to the preposition decoder 60 of row, the function that alignment is selected.Sense amplifier 59 has the function of the data that amplification reads from main memory unit or redundant storage unit.The data of sense amplifier 59 export the outside to by output circuit.

The signal that row address memory circuit 61,61 ' storage is selected the failed row of main memory cell array, relatively the output signal of this signal and preposition decoder 56 of the master that goes and the preposition decoder 57 of row is exported " L " level output signal during unanimity.

The signal that column address storage device 63,63 ' storage is selected the trouble block of main memory cell array, relatively the output signal of this signal and preposition decoder 56 of the master that goes and the preposition decoder 60 of row is exported " L " level output signal during unanimity.

Select circuit 62,62 have according to row address memory circuit 61,61 ' or column address memory circuit 63,63 ' output signal, in the middle of a plurality of controls extremely of redundant memory cell array, select 1 function.

Address translation circuit 64,64 ' have according to column address memory circuit 63,63 ' output signal, in the middle of a plurality of controls of redundant memory cell array extremely, select 1 function, and have according to the preposition decoder 57 of row or be listed as the output signal of preposition decoder 60, the function of control column decoder 58.

Redundancy control circuit 65, redundancy write status signal circuit 66 and SGV/D decoder 67 has the regulation of generation control signal, offers the function of allocated circuit.

Figure 14 illustrates the sequential of reading of Figure 13 semiconductor storage unit.

The address signal that inputs to address pin is latched by the trailing edge of address latch initiating signal ale signal, and this address signal offers the main preposition decoder 56 of row, the preposition decoder 57 of row respectively, is listed as preposition decoder 60 and SGV/D decoder 67.

The preposition decoder 57 of row is output as  A1,  A2,  B1,  B2, SG1～SG4.Here, select for example SG1, have only SG1 to be in " H " level, SG2～SG4 all is in " L " level.

Like this, make among some among  A1 and the  A2,  B1 and the  B2 somely among some and SG1～SG4 to be " H " level, word line is selected.

Figure 15 illustrates the example that the main memory cell array is divided into 4 memory blocks when the main memory cell array word line is selected.

Specifically, main memory cell array is for example having Unit 64 on the column direction, and is divided into memory block 1～4 on column direction.Each memory block has Unit 16.

As shown in table 2, the selection of memory block is to be undertaken by the logic that adopts RA1, RA2, RB1, four signals of RB2.

Table 2

	??RA1	??RA2	??RB1	??RB21
					Memory block
1	????H	????L	????H	????L
					Memory block
2	????H	????L	????L	????H
					Memory block
3	????L	????H	????H	????L
					Memory block
4	????L	????H	????L	????H

Figure 16 illustrates the example that further memory block of main memory cell array is divided into a plurality of memory banks when the word line of main memory cell array is selected.

Specifically, 1 memory bank has Unit 2 for example on the column direction Unit 4 being arranged on the line direction.

As shown in table 3, the selection of memory bank is to four signal fetch logics of SG1～SG4, and adopts SGU, SGD to carry out.SG1～SG4 is used for the Unit 4 on the column direction are selected, and SGU, SGD then are used for the Unit 2 on the line direction are selected.

Table 3

	??RA1	??RA2	??RB1	??RB21
					Memory bank
1	????H	????L	????L	????L
					Memory bank
2	????L	????H	????L	????L
					Memory bank
3	????L	????L	????H	????L
					Memory bank
4	????L	????L	????L	????H

Shown in Figure 17 is the equivalent electric circuit of Figure 15 and memory bank formula mask rom shown in Figure 16.

Each memory bank has Unit 4 at column direction, at line direction Unit 2 is arranged.Alternate configurations has bit line BIT0～BIT3 and alignment COL1～COL4 between each memory bank.

The data of the memory cell that each memory bank is selected read out to bit line BIT0～BIT3.Be added with earthing potential VSS or bias potential on alignment COL1～COL4, memory bank selected by the current potential that is added on this alignment COL1～COL4.

When main memory cell array had Unit 32 on line direction, the memory bank number was 16 on the line direction, and the bit line radical is 8.Thereby, can in the middle of 8 selected memory cell, read 8 data.

As shown in table 4, the selection of word line is by 4 signal fetch logics of  A1,  A2,  B1,  B2 are carried out.

Table 4

	??A1	??A2	??B1	??B21
					????WL1	????H	????L	????H	????L
????WL2	????H	????L	????L	????H
					????WL3	????L	????H	????H	????L
????WL4	????L	????H	????L	????H

As shown in table 5, the selection to Unit 1 in each memory bank line direction Unit 2 is undertaken by SGU and two signals of SGD.

Table 5

Memory cell	????SGU	????SGD
			????a′	????H	????L
????a	????L	????H

(when selecting WL1)

Next with reference to Figure 17 the system of selection of memory cell and the scheme of sense data are described.

At first, utilize  A1,  A2, four signals of  B1,  B2, select word line WL1, word line WL1 is set at " H " level, and other word line WL2～4 are set at " L " level.

And for example giving, alignment COL1 gives alignment COL2 with bias potential with earthing potential.Therefore, only be that the memory cell that is disposed between bit line BIT1 and the alignment COL1 is in readable doing well.

And SG1 is set at " H " level, and SGU is set at " L " level, and SGD is set at " H " level, and the MOS transistor of irising out just is in conducting state, select storage unit b.

Thereby the data of memory cell b read out to bit line BIT1.

When memory cell b writes data (during storage data " 1 "), the threshold setting of this memory cell b gets higher, is added with " H " level current potential even if word line WL1 goes up, and memory cell b does not enter conducting state yet.Thereby bit line BIT1 current potential is guaranteed precharge " H " level current potential in advance, just data " 1 " can be read out to bit line BIT1.

And memory cell b is not when writing data (during storage data " 0 "), and the threshold setting of this memory cell b must be lower, and word line WL1 is added with " H " level current potential, and memory cell b just is in conducting state.Thereby the current potential of bit line BIT1 becomes " L " level current potential (earthing potential VSS) through alignment COL1, and data " 0 " just read out to bit line BIT1.

The outstanding signal of Figure 18 be the part of main memory cell array, shown in Figure 19 is plane pattern when forming Figure 18 circuit on semiconductor chip.

Bit line BIT1, BIT2 and alignment COL1, COL2, COL3 are made of for example aluminium respectively, and SG1 line, SGU line, SGD line and each word line WL1～WL64 are made of for example tungsten silicide respectively.In addition, other parts are by for example imbedding n in the semiconductor chip of nuzzling ⁺Diffusion layer constitutes.

Select storage unit b, and when data " 0 " were stored to memory cell b, memory cell b was in conducting state, bit line BIT1 current potential descends, and data " 0 " can read out to bit line BIT1.

Table 6 illustrates the relation of the same SG1 of selected memory cell, each signal potential of SGU, SGD and alignment COL1, COL2 current potential in the mask rom of Figure 18 and Figure 19.

Table 6

Memory cell	??SG1	??SGU	??SGD	??WL1	??COL1	??COL2
							????a	????H	????H	????L	????H	??Vss	Bias voltage
????b	????H	????L	????H	????H	??Vss	Bias voltage
							????c	????H	????L	????H	????H	Bias voltage	??Vss
????d	????H	????H	????L	????H	Bias voltage	??Vss

Shown in Figure 20 is the circuit structure of main memory cell array part and redundant memory cell array part.

Figure 21 is illustrated in the plane pattern when forming Figure 20 circuit on the semiconductor chip.Shown in Figure 22 is the column decoder part, the circuit structure of write circuit part and reading circuit part.

In addition, (for example CC1～CC4) back is added with this class mark of R/L to signal.This R/L means when the memory cell array on the chip is divided left side and right side (be the left side with 51A, 51B among Figure 13 for example, 51A ', 51B ' are the right side), memory cell array and right side memory cell array on the left of independently controlling with signal separately.

Alternate configurations has alignment COL0～COL8 and the bit line BIT0～BIT7 that extends along column direction in the main memory cell array 71.Also dispose alignment COL9～COL8 of extending along column direction and bit line BIT0, BIT2, BIT4, BIT6 in the redundant memory cell array 74.

Dispose bit line column decoder 72 between main memory cell array 71 and the redundant memory cell array 74 and cut off circuit 73 bit lines have 4 bit lines of selection in the middle of 8 bit lines to decoder 72 function.Cut off circuit 73 and have redundant storage unit 75 is carried out data when writing and reading, between main memory cell array and redundant memory cell array, cut off the function of alignment COL0～COL8.

Column decoder 76 has in the middle of 4 bit lines selects 1 bit line, and selects the function of 3 alignments from 9 alignments.Bias voltage decoder 77 has according to signal CC1R/L～CC4R/L, and the bias potential that bias generator is provided offers the regulation alignment, and the function of earthing potential is provided to remaining regulation alignment.

Sense amplifier adopts the differential type amplifier, by detecting bit line BL1 or alignment CL1 potential change, reads memory cell data.

Write circuit 78 has and gives bit line to write the function of current potential VPP when redundant storage unit writes data.Write circuit 78 also has the function of cutting off sense amplifier (differential type) and alignment when redundant storage unit writes data.

In the semiconductor storage unit of said structure, the alignment of redundant storage unit and the alignment of main memory unit are common.Here, the SRDE R/L of write circuit 78 becomes " H " level from the memory cell sense data of main memory cell array the time, and becomes " L " level during when redundant storage unit writes data with from the redundant storage unit sense data.

In addition, provide required current potential by the bonding pad (pad) that writes pattern detection circuit to Figure 30 data, the signal WCE that recognition data writes becomes " H " level.

Next illustrate to redundant storage unit and write data.

At first, the MOS transistor of cut-out circuit 73 is set at and all is in cut-off state.This is in order to prevent that writing current potential VPP is added on the main memory unit.

By write circuit 78, cut off alignment CL1 and sense amplifier, and give alignment CL1 to write current potential VPP, give alignment CL2 with earthing potential Vss.And WCE is " H " level, and the transistor of bias voltage decoder 77 all ends.

Select 2 adjacent row by column decoder 76, a certain row in these 2 row are provided write current potential VPP, provide earthing potential Vss another row.Among the control grid CON1～CON4 of selection redundant memory cell array 74 any one writes current potential.

For example select CON1, and apply on alignment COL0 and write current potential VPP, apply earthing potential on the alignment COL1, electronics just injects the floating grid of redundant storage unit 75, writes data.

Next illustrate from the main memory cell array sense data.

At first, the MOS transistor of cut-out circuit 73 is set at and all is in conducting state.

Cut off alignment CL1 and sense amplifier by write circuit 78, connect bit line BL1 and sense amplifier.And, by bias circuit and bias voltage decoder 77, provide bias or earthing potential to alignment CL1～CL3.

By column decoder 72,76, select 2 adjacent row, provide bias to a certain example in these 2 row, provide earthing potential Vss to another row.Select any among the word line WL1～WL4 of main memory cell array 71, give high potential.

For example select word line WL1, and apply bias on alignment COL0, COL1 applies earthing potential at alignment, SG1, SGU are set at " H " level, SGD is set at " L " level, and just the data of select storage unit a and memory cell a read out to bit line, deliver to sense amplifier.

Next illustrate from the redundant memory cell array sense data.

At first, the MOS transistor of cut-out circuit 73 is set at and all is in cut-off state.

Connect alignment CL1 and sense amplifier by write circuit 78, cut off bit line BL1 and sense amplifier, CL2 provides earthing potential to alignment.Select adjacent 2 row by column decoder 76, a certain row in these 2 row are connected with sense amplifier, and provide earthing potential VSS another example.And any one gives high potential among the control grid CON1～CON4 of selection redundant memory cell array 74.

For example select control grid CON1, and alignment COL0 is connected with sense amplifier, alignment COL1 applies earthing potential, and select storage unit 75 reads out to alignment COL0 with the data of memory cell 75, delivers to sense amplifier.

Table 7 gathers the level that memory cell is carried out data each signal when writing and reading is shown.

Table 7

	SROE?R/L	CC1?CC2?CC3?CC4	CD1?CD2	CL1?CL2?CL3??BL1	?COL0?BIT0?COL1?BIT1?COL2
						Number is main reads singly to go out unit according to storage	????H ????H ????H ????H	?H???L???L???L ?L???H???L???L ?L???L???H???L ?L???L???L???H	?H???L ?H???L ?L???H ?L???H	The unsteady anxious Vss S/A of the Vss anxious S/A of the floating Vss of the unsteady S/A of the anxious Vss of anxious unsteady S/A	The anxious S/A S/A of the anxious S/A Vss of Vss S/A Vss S/A
The surplus certificate of superfluous number is deposited and is read to store up out the unit	????L			Vss?????S/A
						The surplus certificate of superfluous number is deposited to write and is stored up the unit	????L			VPPD Vss (data " 1 ") floats

In addition, the control grid of redundant storage unit is by imbedding n ⁺Diffusion layer constitutes, thereby resistance value and capacitance are bigger.Therefore, follow the usual practice as imbedding n ⁺Diffusion layer forms wire tungsten silicide (WSi) layer, but also can make this n of imbedding on semiconductor chip ⁺Diffusion layer and tungsten silicide layer short circuit.

In the present embodiment, the bit line number on the redundant memory cell array is set to such an extent that lack than the bit line number on the main memory cell array, thereby carries out the above-mentioned n that imbeds easily ⁺The short circuit of diffusion layer (control board) and tungsten silicide layer.

Shown in Figure 23 is the control grid selection circuit of a row redundant memory cell array.

In Figure 20 circuit, main memory cell array line direction unit 8 is corresponding with redundant cell array line direction Unit 1.Therefore, when the delegation to main memory cell array protects, need 8 row in the redundant memory cell array.

Thereby for the delegation to main memory cell array protects, redundant cell array need be controlled 8 control grids.Therefore, will be taken into the control grid to signal CC1～CC4 (Figure 22), SGU, the SGD (Figure 20) that 8 memory cell of main memory cell array line direction adjacency are deciphered and select circuit, control is to the replacement of control grid.

Order when Figure 24 illustrates main memory unit protected.

At first, the address of selecting the guard rows of main memory cell array is write address storage PROM.Next, in order correctly this address to be write this PROM, test.Specifically, when the end, address of the guard rows of selecting main memory cell array writes this PROM, just carry out writing till correctly writing once more.

Confirm that the address writes, this address date is write redundant storage unit.Next, in order correctly these data to be write redundant storage unit, test.Specifically, when this address date does not write redundant storage unit, just carry out writing till correctly writing once more.

Then repeat this write activity, till whole addresses and data thereof write end.

Next, simple declaration will write the method for address storage with PROM to main memory cell array guard rows or the address of protecting piece to select.

Signal  A,  B, SG, RA, the RB of row address memory circuit input nominated bank direction address.The column address memory circuit is also imported signal CA, CB, the CC of specify columns direction address and is listed as the main address RA of row, the RB that (piece) selected.

Figure 25 illustrates the row address memory circuit, and Figure 26 illustrates the column address memory circuit.

Each address storage circuit inserts 12 holding wires (wherein only 5 be " H " level).When PROM Write fault address is used in the address storage, provide high potential (for example 6V) to memory cell control grid.

Here, employing level shifter as shown in figure 27.By on the power supply VPP of this level shifter, adding high potential, make that the output signal of level shifter is a high potential.

Figure 28 represents to write fashionable block diagram.

12 decoding lines are input to the row, column address storage circuit as incoming line.That is, in the row address memory circuit, use output CA, CB, the CC of the preposition decoder of row, and do not use output  A,  B, the SG of the preposition decoder of row.So, there is no need the output signal of the preposition decoder of row is provided with level shifter.

Figure 29 presentation address is write fashionable sequential chart.Figure 30 represents the writing mode testing circuit.

Utilize predetermined potential to add to the bonding pad of writing mode testing circuit, test signal is risen, the signal WAE that identification address writes becomes " H " (height) level.Because this signal WAE becomes " H " level.Die as shown in figure 28, the address is write fashionable signal kinds and is become " during routine ".

Then,, latch the address of the memory cell that should protect by the trailing edge of address latch initiating signal, and specify row, column with about each 2, add up to 8 address storaging unit group's address.Specify this address storaging unit group's decoder to be output as WFA1, WFA2, WFB1, WFB2.

As shown in table 8, on VPPG1, VPPG2, VPPD, add 6V, 3V, 8V respectively.

Table 8

	The address storage is write fashionable with the unit	During address latch	Storage is write fashionable with the unit	When reading
					??VPPG1 ??VPPG2 ??VPPD ??VDD	????6V ????3V ????8V ????3V	????3V ????3V ????3V ????3V	????3V ????6V ????8V ????3V	????3V ????3V ????3V ????3V

Here,, then have only the selected line of output to become " H " level, be somebody's turn to do the level shifter of the current potential of " H " level, become 6V by Figure 27 according to preposition decoder of row and the main decoder of row in case CE becomes " L " level from " H " level.Thus, have only the grid of the memory cell of address storage circuit storage to be set at 6V among Figure 25 and Figure 26.

Then, CE becomes " L " level, and behind the delayed circuit delay 200ns, selected WFA, WFB become " H " level.The decoding output of this WFA, WFB also has level shifter shown in Figure 27, and therefore, VPPD becomes 8V.

The time that adds to grid for the time ratio that makes current potential add to the drain electrode of EPROM is slow, so insert delay circuit, like this, is added with VPPD in an address storaging unit group's the drain electrode.

Figure 31 is the potential diagram that is in write state.

In this embodiment, simultaneously 5 unit are write.Because to write identification signal WA be " H " level in the address, so the control circuit by Figure 32, VGN becomes " L " level, and the current potential of VPPD can not passed to testing circuit.Utilize the sequential of Figure 29, the address that should protect all deposits in.

Below, address check is described.

The sequential of Figure 33 presentation address verification.Write fashionable equally with the address, in case add current potential on the bonding pad of writing mode signal deteching circuit among Figure 30, address check signal WCAC just becomes " H " level.

Shown in above-mentioned table 8, VDD adds to VPPG1, VPPG2, VPPD.By the trailing edge of address latch initiating signal, latch the address of previously stored protection memory cell.

As shown in figure 34, in case latch, the output of preposition decoder just is input to address storaging unit.

Figure 35 represents the sequential of redundancy control circuit.

In the redundancy control circuit of Figure 32, in case ALE is " L " level, VGN just becomes the intermediate value current potential.It is redundant to begin to detect row.Figure 34 represents this operating state.Because VGPR is " L " level, so to producing precharge with the drain electrode that the unit connects altogether with the address storage.As an example, here, suppose  A1,  B1, SG1, RA1, RB1 are produced and write.Wherein, in case  A1,  B1, SG1, RA1, RB1 are " H " level, Quan and other be " L " level, promptly no matter which PROM does not have electric current to flow, so the drain potential of public connection becomes " H " level.

On the other hand, import under the situation of different addresses, as when  A2 be " H " level, when  A1 is " L " level, with  A2 be grid PROM owing to threshold value low, so flow through electric current, it connects drain potential altogether and becomes " L " level.Have again, the PROM that does not fully write, also because electric current is flow through in starting, and the drain electrode of public connection is become " L " level.

Here,, just stop precharge, output " L " level when connecing drain electrode altogether, output " H " level when connecing drain electrode altogether for " L " level for " H " level if VGPR becomes " H " level from " L " level.

This output is input to the NAND circuit shown in Figure 13 block diagram.This output is when be " H " level entirely, also is the address of storage usefulness unit, writing line address and Input Address when inconsistent, or writes the address and store when not becoming " H " level fully with threshold value among the PROM of unit, and output signal SRDRR/L becomes " L " level.

This signal is input to redundancy control circuit among Figure 32, makes VGPCR/L become " L " level, begins to detect piece (row) redundancy.Detection method is identical with line direction.

On the other hand, it is consistent with Input Address with the address of unit to write the address storage, and when using row redundant, SRDRR/L becomes " H " level.This signal is if be input to redundancy control circuit among Figure 32, and then VGPCR/L can not become " L " level, does not detect the piece redundancy.

As mentioned above, detect row and piece redundancy.When output signal was given redundancy by the logic of Figure 13, this logic output SRDER/L became " H " level, and when not giving redundancy, SRDER/L becomes " L " level.

Here, be connected to R/L after the SRDE, just be present in the row decoder left side (I/01, I/02) and (I/03, main memory cell array I/04), this R/L are in order to protect (giving redundancy) each memory cell etc. respectively on the right side.

Therefore as seen, import and be stored in the address identical address of address storage, and SRDER/L writes when being " L " level, on the contrary, when SRDE is " H " level, do not write with the unit.

Below, writing of data is described.

Figure 36 represents that data write fashionable sequential.

Write identically with the address, apply predetermined potential, make data write signal WCE become " H " level by bonding pad A～C to Figure 30 writing mode signal deteching circuit.

Shown in above-mentioned table 8, respectively VPPG1, VPPG2, VPPD, VDD are added to 3V, 6V, 8V, 3V.

Then, latch with the trailing edge of address latch initiating signal ALE of enabling the protection address, because of to write fashionable institute address stored consistent with the address, so identical action when carrying out with address check, the signal of SRDE becomes " L " level.

Shown in block diagram among Figure 13, with redundant memory cell array in abutting connection with have row with and row with 2 address storage circuits, the output of each address storage circuit of row and column is input to the NAND circuit.When the output of 2 address storage circuits all is " H " level, promptly deposit the address storage in the address of unit and Input Address when inconsistent, the output RW1 of above-mentioned NAND circuit is " L " level.On the other hand, when certain side's address storage circuit was output as " L " level in row or the piece (row), when promptly giving redundancy, RW became " H " level.

Redundant storage unit control gate control circuit among this RW signal input Figure 23 with the signal of CCiL/R and SGU/D, makes a control gate become high level.Redundant storage unit control gate control circuit is because of having the level shifter among Figure 27, so " H " level of control gate becomes VPPG2.

In the redundancy of being expert at, column selection is identical with the column selection of main memory unit to be carried out.

Figure 37 represent among Figure 13 the preposition address translation circuit 64,64 of row ' structure.

When routine is read and row redundancy unit when reading, the SRDCR/L signal be " L " level, so export output signal CA, CB, the CC that is listed as preposition decoder.

When the piece redundancy unit was read, the SRDCR/L signal was " H " level, so export  A,  B, SG.These output signals CAiR/L, CBiR/L are input to decoder, and CCiR/L input control gate is selected circuit, carries out column direction and selects.

The output that is listed as preposition address translation circuit also has the level shifter among Figure 27, and the output of " H " level becomes VPPD.Select by this column direction, carry out the selection of redundant storage unit.

Shown in Figure 36 sequential, after the Input Address, be added with the data of protection memory cell on the address pin.

At this moment, if CE is " L " level, when the audio data AD i that had then before added to was " H ", write circuit 78 in Figure 22, and CL1 becomes VPP, and becomes VPP by the drain electrode of 76, one redundant storage units of column decoder, writes.When ADi was " L " level, VPP did not impose on the drain electrode of redundant storage unit, so do not write.By this operation, big redundant storage unit writes predetermined data.

Then, the data that write redundant storage unit are verified, and before data all write, constantly repeated to write again.

From the method for redundant storage unit sense data be, Input Address, with predetermined storage unit in this address visit main memory cell array, simultaneously, address storage circuit detects the address.

Described method was identical when this method was surveyed with the school, address.Here, when giving redundancy, switch to the selection redundant storage unit.The system of selection of data cell, the system of selection of writing fashionable memory cell with data is identical.

But data are write fashionable, and alignment inserts VPPD, and data are when reading, and alignment inserts sense amplifier.

Though the selection of redundant storage unit is slower than the selection of main memory unit, because of the access time weak point of redundant storage unit, so can prevent from the slack-off problem of redundant storage unit sense data.

But, as shown in figure 38, after finishing checking, make the contact pin of defending of VPPG1, VPPG2, VP-PD, VDD be connected in a VDD bonding pad by closing line, during conventional the action, make and have only VDD to add to the VDD bonding pad.

Figure 39 represents the block diagram of semiconductor storage unit of the present invention.

Be prerequisite in this embodiment with the mask rom.Below, be simplified illustration, setting main memory cell array has 32 unit on line direction, 64 unit are arranged on column direction, and have 4 I/O terminals.

The structure of this semiconductor storage unit at first, is described.

This embodiment compares with above-mentioned example, and its difference is the row and column address storage circuit is merged into one as address storage circuit, and by cutting off circuit the preposition decoder of row and column is linked to each other.

Main memory cell array 51A, 51B, 51A ', 51B ' are by according to having or not storage and the different a plurality of MOS transistor of threshold value constitute.Redundant memory cell array 52A, 52B, 52A ', 52B ' are by according to having or not storage and the different a plurality of one-level PROM of threshold value constitute.According to this configuration, the alignment of main memory cell array and redundant memory cell array is shared, and column decoder also can be shared, and this is in order to make main memory cell array and redundant memory cell array close, thereby can help to dwindle semi-conductive chip.

Constituting main memory unit with MOS transistor, constituting the occasion of redundant storage unit with one-level PROM because the size of MOS transistor and varying in size of one-level PROM, so the size of the line direction of one-level PROM can be set at MOS transistor the line direction size 2 ⁿDoubly.

For example, as this embodiment, be set at 8 times of line direction size of MOS transistor in size with the line direction of one-level PROM, and dispose on the line direction of a main memory cell array under the situation of 32 unit, if 4 unit of configuration on the line direction of a redundant memory cell array, then the spacing of the row of redundant memory cell array is 8 of spacing of the row of main memory cell array, this be for the width of the line direction that makes redundant memory cell array consistent with the width of the line direction of main memory cell array.

Around main memory cell array 51A, 51B, 51A ', 51B ' and redundant storage unit 52A, 52B, 52A ', 52B ', dispose bit line column decoder 53,53 ' and cut off circuit 54,54 '.

Bit line column decoder 53,53 ', because the columns of main memory cell array 51A, 51B, 51A ', 51B ' is more than the columns of redundant memory cell array 52A, 52B, 52A ', 52B ', so have the columns that reduces main memory cell array 51A, 51B, 51A ', 51B ', the function that is connected with redundant memory cell array 52A, 52B, 52A ', 52B '.

In the time of in the memory cell that data is write redundant memory cell array 52A, 52B, 52A, 52B ', or during from this memory cell sense data, cut off circuit 54,54 ' the have function of between main memory cell array and redundant memory cell array, cutting off alignment.

Row decoder 55,55 ' have the output signal according to main preposition decoder 56 of row and the preposition decoder 57 of row is selected the function of the word line of main memory unit 51A, 51B, 51A ', 51B '.

Column decoder 58 has the output signal according to the preposition decoder 60 of row, selects the function of alignment.Sense amplifier 59 has the function of the data that amplification reads from main memory unit or redundant storage unit.The data of sense amplifier 59 output to the outside by output circuit.

Address storage circuit 70, the 70 ' signal of out of order row or piece in the selection main memory cell array is selected, and with this signal with the main preposition decoder 56 of row and preposition decoder 57 of row or the main preposition decoder 56 of row and be listed as that output signal compares in the preposition decoder 60, the output signal of output " L " level when consistent.

Select circuit 62,62 ' have according to address storage circuit 70,70 ' output signal, select one function in a plurality of control grids in the redundant memory cell array.

Address translation circuit 64,64 ' have according to address storage circuit 70,70 ' output signal, select one function in a plurality of control grids in the redundant storage unit, have simultaneously according to the preposition decoder 57,57 of row ' the function of output signal control column decoder.

Cut off circuit 71,72 according to being line direction or transposing column direction in the transposing main memory cell array, or according to whether data being write in the redundant storage unit, or, determine logical and disconnected according to being from the main memory cell array sense data or from the redundant memory cell array sense data.

Redundancy control circuit 65, redundancy write status signal circuit 66 and SGV/D decoder 67, have to generate the function that predetermined control signal is supplied with predetermining circuit.

Figure 40 represents redundancy control circuit, and Figure 41 presentation address memory circuit, Figure 42 are represented the sequential of reading of semiconductor storage unit among Figure 39.

In the present embodiment, compare with above-mentioned example, its different characteristic is, row address memory circuit and column address memory circuit are merged into one as address storage circuit; Be provided with the output signal that is used to switch the preposition decoder of row and column, and offer the cut-out circuit of address storage circuit.

Here, set forth the address reading method.

As reading among Figure 42 shown in the sequential, make ALE become " L " level from " H " level after, VGN becomes the intermediate value current potential, VGRR/L becomes " L " level, so detect storage unit, address.At this moment, GR is " H " level, and GC is " L " level, so the line direction protection is input to storage unit, address with the address.Thus, detect the memory cell of line direction.

Here, when giving the row redundancy, the signal of SRDRR/L still is original " H " level, so VGPR/L is fixed in " H " level by the circuit of Figure 40, does not detect the piece redundancy.

Another branch, when not giving the row redundancy, the signal of SRDRR/L becomes " L " level, thereby electric circuit inspection piece (row) redundancy of Figure 40.At this moment, GR is " L " level, and GC is " H " level, so the column direction protection equals to deposit in storage unit, address with the address.Thus, the column direction memory cell is protected.

Storage unit in address among Figure 41 is compared with the unit with address storage among Figure 25, if difference is to have the PROM of grid input GR, GC signal.Thus, difference row and piece.

In the above-described embodiments, redundant memory cell array is near the column direction configuration of main memory cell array, so but the array common column decoder of main memory unit and redundant storage unit.

Yet in the following embodiments, redundant memory cell array and main memory cell array are configured on the position spaced apart from each other, and in main memory unit and redundant memory cell array column decoder are set respectively, describe with regard to this situation below.

In this embodiment,, as shown in figure 43, select the decoder of redundant storage unit, also can only select to be connected to the bit line of redundant storage unit source electrode though be necessary to constitute respectively the column decoder of main memory cell array and the column decoder of redundant memory cell array.Alignment be there is no need decoding, so can be connected to VSS altogether.

Therefore, resistance does not insert the source electrode of redundant storage unit, has improved write diagnostics, has shortened the write time.And this alignment there is no need every unit and all is provided with, and also can be provided with one in per Unit two.Therefore, can shorten the length of column direction in the redundant memory cell array.Until now, because the row grid of adjusting is in separate state,, can increase the unit number that to protect on each I/O so redundant memory cell array only can be used for an I/O.

Figure 44 represents the block diagram of semiconductor storage unit of the present invention.

In this embodiment, redundant memory cell array can be finished row, piece, reach the protection that is listed as.Address storage is identical with above-mentioned example with the unit, its structure energy storage line, column address both.

The size of the base unit of row protection and block protection, identical with above-mentioned all examples, during the row protection, word line is one (64 unit), and during block protection, line direction is 2 unit, and column direction is 16 unit.During the row protection, line direction is a unit, and column direction is 64 unit.

In the present embodiment, redundant memory cell array, I/O0, I/O1 use have that 2, I/O2, I/O3 use have 2.Another big difference is, configuration cuts circuit not between main memory cell array and redundant memory cell array, in case become redundant mode, just the transistor by the sense amplifier front switches.

The address playback mode is identical with previous address storage circuit common type, and it is redundant also to detect row during the piece redundancy detection simultaneously.Sequential is identical with the sequential of Figure 42.

As shown in figure 45, the address storage only increases by 2 unit with the unit, so that difference is listed as the unit of adjacent column direction when protecting.When protection row and block protection, because select without SGU, SGD, 2 unit write simultaneously.During the row protection, the main preposition decoder of need not going is selected, so RA2, RB1, the RB2 of its whole signal RA1 write.

When row protection and block protection; identical with above-mentioned all embodiment; because the whole interchangeable in left side or right side of cell array; the sense amplifier of each I/O so output that will redundant cell array is led respectively; but during the row protection; have I/O shown in Figure 44 block diagram storage with unit 81,81 ' and testing circuit 83,83 ', be used for the output of redundant storage unit is connected to the sense amplifier of certain I/O.

When row and block protection, this I/O storage or not with unit 81, but is listed as when protecting, and the I/O that connects the output of redundant memory cell array is stored in here, and this output is generally " H " level, enters the row protection when becoming " L " level, the switching decoder.

When being expert at protection and block protection, select the signal of circuit 62,62 ' middle access SGU/D, by SGU/D, RB translation circuit 82,82 ' it is switched to the capable signal RB1 of selection main memory unit, RB2.

Row grid 80,80 in the input redundant memory cell array ' example identical of signal and common column grid, during the row protection, insert the signal of the preposition decoder of row, during block protection and during the row protection, insert and go the signal of preposition decoder.

In the above-described embodiments, though set forth, also can be used as the redundant circuit of EPROM, EEP-ROM or DRAM etc. with regard to mask rom.

The drawing reference symbol of each inscape mark in the application's claims is for the ease of understanding the present invention, and this mark and not meaning that is defined in technical scope of the present invention in the drawing illustrated embodiment.

As mentioned above, has following effect according to semiconductor storage unit of the present invention.

The first, by redundant memory cell array being disposed at the end of column direction in the main memory cell array (or line direction).The cut-out circuit of configuration cuts bit line or alignment between main memory unit and redundant memory cell array, and then at the end of redundant memory cell array configuring arrange decoder, therefore, can lead, a shared column decoder in the redundant memory cell array, can dwindle chip area.

In this case, especially, if use one-level PROM to constitute the redundant storage unit of mask rom, just can form the grid of main memory unit (MOS transistor) and the floating grid of redundant storage unit (one-level PROM) simultaneously, do not increase manufacturing process, and can dwindle chip area.

Second; by redundant memory cell array only being configured in an end of column direction in the main memory cell array (or line direction); can connect the output line of the preposition decoder of row and the output line of the preposition decoder of row by the crystal nest of tubes; control the switching of this crystal nest of tubes; with the output of the preposition decoder of row or be listed as the output access address memory circuit of preposition decoder; thus, can realize the row protection and the row protection of main memory cell array.

Thus, with for can row, column protection and comparing in the situation of the both ends configuring redundancy memory cell array of the row, column direction of main memory cell array, can reduce chip area.

Claims (15)

1. semiconductor storage unit, it is characterized in that, comprising: main memory cell array, the row decoder of the row of described main memory cell array being selected according to first input signal, near the end configuration of the column direction of described main memory unit and with the redundant memory cell array of described main memory cell array shared bit line or alignment, be configured in the cut-out circuit between described main memory cell array and described redundant memory cell array, in abutting connection with the configuration of described redundant memory cell array and the row of described main memory cell array are selected and according to described first or described second input signal column decoder that the row of described redundant memory cell array are selected and the row of described redundant memory cell array is selected and utilized the redundant circuit of described cut-out circuit according to second input signal at described main memory cell array and separated described bit line of described redundant memory cell array or described alignment according to described first or second input signal.

2. semiconductor storage unit as claimed in claim 1, its feature are that also described main memory cell array is made of the mask rom that can only finish read operation, and described redundant memory cell array is made of one-level PROM.

3. semiconductor storage unit as claimed in claim 2, its feature also be, in described redundant memory cell array, with two publicly-owned source and drain areas of memory cell of column direction adjacency.

4. semiconductor storage unit as claimed in claim 1, its feature also be, the size of the line direction of described redundant memory cell array is the integral multiple of size of the line direction of described main memory cell array.

5. semiconductor storage unit as claimed in claim 1, its feature also is, described redundant circuit has the storage area of the row of the defective memory cell that is used to store described main memory cell array, going and the capable consistent occasion of utilizing described first input signal to select of the described storage area of storage, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array.

6. semiconductor storage unit as claimed in claim 1, its feature also is, described redundant circuit has the memory cell of the row of the defective memory cell that is used to store described main memory cell array, the occasion that the row of storing in described memory cell are consistent with the row that utilize described second input signal, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array, simultaneously described first input signal is delivered in the described column decoder, selected the row of redundant memory cell array according to described first input signal.

7. semiconductor storage unit as claimed in claim 1, its feature also is, by the first and second crystal nest of tubes, transmitting the holding wire of described first input signal and the holding wire of described second input signal of transmission interconnects, described column decoder is connected on the holding wire between the described first and second crystal nest of tubes, by means of control the described first and second crystal nest of tubes conducting and end, described first or second input signal is sent in the described column decoder.

8. semiconductor storage unit as claimed in claim 1, its feature also is, described redundant circuit has the row of the defective memory cell that is used to store described main memory cell array or the memory cell of row, row of in described storage area, storing or row and row that utilizes described first or second input signal to select or the consistent occasion of row, utilize described cut-out circuit to disconnect described bit line or described alignment, and select the row of described redundant memory cell array, simultaneously described first or second input signal is delivered in the described column decoder, selected the row of described redundant memory cell array according to described first or second input signal.

9. semiconductor storage unit as claimed in claim 1, its feature also is, by first, the second and the 3rd crystal nest of tubes, transmitting the holding wire of described first input signal and the holding wire of described second input signal of transmission interconnects, described column decoder is connected on the holding wire between the described first and second crystal nest of tubes, the selection circuit of the row of described cut-out circuit and described selection redundant memory cell array is connected on the holding wire between the described second and the 3rd crystal nest of tubes, by means of control described first, the conducting of the second and the 3rd crystal nest of tubes and ending, described first or second input signal is sent in the described column decoder, and first or second input signal is sent in the described selection circuit.

10. semiconductor storage unit as claimed in claim 1, its feature also is, described semiconductor storage unit has the bit line and the alignment of mutual configuration, described main memory cell array is made of the memory cell that is connected between bit line and the alignment, described redundant memory cell array is made of the memory cell that is connected between alignment and the alignment, the alignment of described bit line and regulation is connected in the sense amplifier, and described alignment is connected to be provided in the biasing circuit of regulation current potential each alignment.

11. semiconductor storage unit as claimed in claim 1, its feature also is, when the data of the memory cell of reading described main memory cell array, described biasing circuit alternatively is applied to earthing potential and bias potential on the described alignment, when the data of the memory cell of reading described redundant memory cell array, described biasing circuit makes described alignment be added with earthing potential every one, and the alignment that will not apply earthing potential is connected in the sense amplifier.

12. semiconductor storage unit as claimed in claim 1, its feature also is, comprise and provide the regulation current potential described alignment, and data are write the write circuit of using in the memory cell of described redundant memory cell array, when the said write circuit write data in the memory cell of described redundant memory cell array, described redundant circuit utilized described cut-out circuit to disconnect described bit line or described alignment.

13. semiconductor storage unit as claimed in claim 1, its feature also is, outer more than one first bonding pad that the current potential that data write the memory cell of described redundant memory cell array and provide uses and more than one second bonding pad that is used to add the power supply potential that makes the semiconductor storage unit running of adding as is provided, after data are write the memory cell of described redundant memory cell array, described power supply potential is applied on described first bonding pad and described second bonding pad simultaneously.

14. semiconductor storage unit as claimed in claim 1, its feature also is, for the radical by bit line in the described redundant memory cell array or alignment is lacked than the radical by bit line in the described main memory cell array or alignment, decoder is configured between described redundant memory cell array and described main memory cell array.

15. semiconductor storage unit, it is characterized in that, comprising: main memory cell array, the row decoder of the row of described main memory cell array being selected according to first input signal, the column decoder of the row of described main memory cell array being selected according to second input signal, redundant memory cell array, redundant circuit of the row of described redundant memory cell array being selected according at least one signal in described first and second input signals and the column decoder of the row of described redundant memory cell array being selected according to described first or second input signal.

Images